Duplominona trimera Curini-Galletti, 2020

Curini-Galletti, Marco, Carcupino, Marcella, Stocchino, Giacinta A., Leasi, Francesca & Norenburg, Jon L., 2020, New species of Duplominona Karling, 1966 (Platyhelminthes, Proseriata) from the Pacific coast of Panama, Zootaxa 4881 (3), pp. 482-498 : 488-490

publication ID

https://doi.org/10.11646/zootaxa.4881.3.3

publication LSID

lsid:zoobank.org:pub:8A41020C-A131-4163-B3C6-D3398647EB4B

DOI

https://doi.org/10.5281/zenodo.4329707

persistent identifier

https://treatment.plazi.org/id/03B42573-FFC1-2062-FF56-F963AC17FA16

treatment provided by

Plazi

scientific name

Duplominona trimera Curini-Galletti
status

n. sp.

Duplominona trimera Curini-Galletti n. sp.

( Fig. 5 View FIGURE 5 )

Holotype. Gulf of Panama, Playa Venado (Veracruz, Panama)(Lat. 8°53’27.07”N; Lon. 79°35’44.16”W), intertidal in silty coarse sand, December 2011: one specimen sagittally sectioned ( USNM 1622585 View Materials ) GoogleMaps

Paratypes. Same data as holotype, five specimens sagittally sectioned ( USNM 1622586 View Materials ; USNM 1622587 View Materials ; USNM 1622588; USNM 1622589 View Materials ; USNM 1622590 View Materials ) GoogleMaps .

Other material. Same data as holotype, three specimens observed alive, and prepared as semi-permanent mounts. Gulf of Panama: Iguana Island (Lat. 7°37’45.33”N; Lon. 79°59’51.05”W), lower intertidal in coarse sand, February 2016, one whole mount ( USNM 1622591 View Materials ), two specimens sagittally sectioned ( USNM 1622592 View Materials ; USNM 1622593 View Materials ); two specimens observed alive, and prepared as semi-permanent mounts GoogleMaps .

Etymology. The name derives from the greek trimeros (three parts) and refers to the to trichotomous tail of the new species.

Description. A rather large and sturdy Duplominona , about 2.5 mm long. With both dot-like and rod-like rhabdoids. Caudal end tripartite, with numerous adhesive glands all along its length ( Fig. 5 A View FIGURE 5 ). Morphology of the three ‘tails’ highly variable, according to movement and adhesion, from short and stubby to narrowly elongate ( Fig. 5 F, G View FIGURE 5 ). Short pharynx at midbody.

Male genital system. With 6–10 testes in two symmetrical rows. With an elongate copulatory organ, up to 85 μm long, lined by a thin muscular layer. With a large spiny cirrus, up to 65 μm long, provided with numerous spines and a tubular stylet ( Fig. 5 B View FIGURE 5 , I–K). The stylet is formed by the distal part of the ductus ejaculatorius, which is everted within the cirrus. On the outer side of this duct the epithelium is absent, and the basal lamina is thickened, producing a hard-tube-like structure, 40–55 μm long, and 13–20 μm wide at its basis ( Fig 5 M View FIGURE 5 : s). The distalmost part of the everted ductus ejaculatorius is provided with numerous, densely packed small, scale-like spines, 1.5 –3 μm in length, arranged in about 8 rows ( Fig. 5 View FIGURE 5 B–D, I–K: ds). Numerous, larger spines are present proximally, surrounding the stylet in its inverted conditions ( Fig. 5 B, I, K, M View FIGURE 5 : ps). These are arranged in 15–20 rows of densely packed, acutely triangular spines, 6.5–10 μm long, with a basis up to 2.5 μm wide ( Fig. 5 E View FIGURE 5 ). Proximally, smaller spines, 3–4 μm long, may be present.

Accessory organ 35–50 μm across, lined by a thin muscular layer. Its position varied in the specimens studied, from lateral to the copulatory organ to just posterior to it ( Fig. 5 G, I View FIGURE 5 : ao). The stylet is acutely pointed, 24–32 μm long. The accessory organ opens to the outside with its own pore, almost midway between male and female pores.

Female genital system. Ovaries and vitellaria as previous species. With a spherical bursa nearly halfway between pharynx and copulatory organ, lined with high, vacuolated epithelium. Vaginal duct long and broad, caudally oriented in most sectioned specimens, and surrounded by a thick muscle layer ( Fig. 5 C, L View FIGURE 5 : vd). The female duct continues posteriorly and opens through the female pore.

Karyotype. With n=3. Karyotype formula: FN=5; Chromosome I: 44.86 ± 1.03; 45.62 ± 2.01 (m); Chromosome II: 36.03 ± 1.5; 46.95 ± 1.16 (m); Chromosome III: 19.1 ± 2.47; 7.81 ± 2.51 (a) (based on four plates, from two specimens from Playa Venado)( Fig 5 H View FIGURE 5 ).

Diagnosis. Species of Duplominona with tripartite tail. With up to 10 testes arranged into two rows. With a large cirrus provided with a tubular stylet 40–55 μm, surrounded by 15–20 rows of acutely triangular spines, 6.5–10 μm long. With few rows of small, densely packed spines on top of stylet. With a spherical bursa in front of the copulatory organ and external vagina; vaginal duct long, wide, and muscular. Accessory organ stylet 24–32 μm long. Karyotype with two large metacentric pairs and one pair of heterobrachial chromosomes. Pore index: a: b: c: d = =3: 2.5: 1: 1.